1. Field of the Invention
The present invention relates to sheet material dispensers in general. More particularly, the present invention relates to sheet material dispensers capable of transferring dispensing from a first mode wherein sheet material is dispensed from a first sheet material supply to a second mode wherein sheet material is dispensed from a second sheet material supply, and a method of transfer.
2. Background of the Invention
Sheet material dispensers are designed to dispense sheet material from various sources including folded sheet material and rolled sheet material. Each type of sheet material source requires a different means of loading and dispensing the sheet material. As a result, each source creates unique refilling problems for maintenance personnel.
Folded sheet material dispensers contain separate sheets of folded sheet material that are dispensed through an opening. Although most of these types of i dispensers are relatively simple, there are drawbacks associated with using folded sheet material because this type of sheet material can be relatively expensive and occupy a rather large volume. In addition, dispensers containing folded sheet material generally need to be filled more often than other dispensers because they permit dispensing of multiple folded sheets simultaneously.
The most common type of sheet dispensers have sheet material wound on rolls. These dispensers have several different means of dispensing paper. The sheets can be removed by either pulling on a free end of a sheet or actuating a lever to advance the sheet. To increase sheet material supply, many roll dispensers are capable of holding two rolls of sheet material. These dispensers often require complicated transfer systems to switch dispensing from one roll to another. One type of transfer system uses a mechanism to detect tension in sheet material from a first roll. Once the tension is removed from the sheet material, indicating the first roll is empty, the mechanism pivots, thereby moving a free end of sheet material from the second roll of sheet material into engagement with a dispensing mechanism. Another type of transfer system involves a transfer mechanism including a complex follower arm, which follows the decreasing diameter of the first roll. Upon depletion of the first roll, the mechanism moves the free end of sheet material from the second roll into engagement with a dispensing mechanism. Both of these types of transfer systems, however, have complex transfer mechanisms and require a relatively long time to load the sheet material rolls.
As a result, maintenance personnel sometimes bypass the transfer system by only maintaining a single roll of sheet material in the dispenser. This has the effect of increasing the number of maintenance checks. This also sometimes leads to a new roll of sheet material being loaded in place of a used roll of sheet material, which is discarded while still having at least some usable sheet material thereon. Such practice can result in significant unnecessary waste of usable sheet material.
It is accordingly a primary object of the invention to provide a simple transfer system that requires minimum time to set up by maintenance personnel.
It is another object of the invention to provide a simple method of transferring between a first roll and a second roll of sheet material.
Accordingly, the present invention is directed to a sheet material dispenser with a transfer system and a method of transferring dispensing from a first mode where sheet material is dispensed from a first source of sheet material and to a second mode where sheet material is dispensed from a second source of sheet material.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention includes a dispenser for dispensing sheet material. The dispenser includes a housing defining an interior for accommodating first and second sources of sheet material, and an outlet through which the sheet material is dispensed. A first rotatable roller is in the housing, and a portion of the sheet material is in contact with the first roller prior to being dispensed through the opening. A transfer mechanism is configured to transfer dispensing of sheet material from a first mode wherein sheet material is dispensed from the first source to a second mode wherein sheet material is dispensed from the second source. The transfer mechanism includes a second rotatable roller which has a slot passing completely through the second roller to retain a free end portion of the sheet material from the second source when the sheet material is dispensed in the first mode.
In another aspect, the first roller has at least one recessed portion, and the second roller has at least one raised portion aligned with the recessed portion. The recessed portion and the raised portion are configured such that when the sheet from the first source covers the recessed portion the transfer mechanism does not transfer dispensing from the first mode to the second mode.
In an additional aspect, the first roller has a first surface, and the second roller has a second surface. The second surface contacts sheet material on the first surface during at least dispensing in the first mode.
In a further aspect, the first surface has a higher coefficient of friction than a coefficient of friction of the second surface.
In yet another aspect, the first surface is formed from rubberized material.
In an additional aspect, the second surface is formed from plastic material.
In another aspect, the transfer mechanism includes at least one biasing element biasing the second roller toward the first roller.
In a further aspect, the dispenser includes a third roller. The third roller forms a nip with the first roller, and the sheet material passes through the nip during dispensing in the first and second modes.
In an additional aspect, the dispenser includes a driving mechanism configured to rotate at least one of the first and third rollers.
In a further aspect, the driving mechanism includes a manually driven element.
In another aspect, the driving mechanism includes an electric motor coupled to one of the first and third rollers.
In a further aspect, the dispenser includes a shield. The shield limits contact between the free end of sheet material from the second source and the first roller before the transfer mechanism transfers dispensing to the second mode.
In yet another aspect, the transfer mechanism is configured to transfer dispensing from the first mode to the second mode when sheet material from the first source is not between the first and second rollers.
In another aspect, the second roller is configured to rotate when sheet material from the first source departs from between the first and second rollers.
In an additional aspect, the third roller includes a cutter for cutting the sheet material.
In another aspect of the present invention, the dispenser includes a housing defining an interior for accommodating first and second sources of sheet material, and an outlet through which the sheet material is dispensed. A first rotatable roller in the housing has at least one recessed portion. A portion of the sheet material is in contact with the first roller prior to being dispensed through the opening. A transfer mechanism is configured to transfer dispensing of sheet material from a first mode wherein sheet material is dispensed from the first source to a second mode wherein sheet material is dispensed from the second source. The transfer mechanism includes a second rotatable roller having a retainer to retain a free end portion of sheet material from the second source when the sheet material is dispensed in the first mode. The second roller has at least one raised portion aligned with the recessed portion. The recessed portion and the raised portion are configured such that when sheet from said first source covers the recessed portion the transfer mechanism does not transfer dispensing from the first mode to the second mode.
In another aspect, the second roller has at least one second raised portion opposite the at least one first raised portion. The second raised portion is configured such that when sheet from the second source covers the recessed portion the second roller is oriented to receive a sheet from a new source.
In yet another aspect, the present invention includes a method of dispensing sheet material. The method includes providing a dispenser containing first and second sources of sheet material. The dispenser further includes a first rotatable roller having at least one recessed portion, and a second rotatable roller having at least one raised portion, the second roller having a retainer. The method includes dispensing sheet material from the first source by passing the sheet material between the first and second rollers, and retaining, in the retainer on the second roller, an end portion of sheet material from the second source. The method includes limiting rotation of the second roller by contacting the raised portion of the second roller against the sheet material between the first and second rollers. The second roller is placed in contact with the first roller when sheet material from the first source is no longer between the first and second rollers. The second roller rotates to feed sheet material from the second source onto the first roller to permit dispensing of sheet material from the second source.
In another aspect, the dispenser includes a third rotatable roller. The third roller forms a nip with the first roller, and the method includes passing sheet material through the nip.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.